In recent years, a technology in which an imaging device, such as a camera, is mounted on the outside of an aircraft, such as a helicopter, an airplane, or an airship, and the ground is imaged from the above using the imaging device is widely known.
When a subject is imaged by the imaging device mounted on the aircraft, a shaking disturbance that is external force, such as vibration of the aircraft itself and vibration due to turbulence, and a posture change generated by the vibration of the aircraft itself and the turbulence are transmitted to the imaging device, and thus, a captured image sometimes became indistinct.
An attempt to reduce the influence of the shaking disturbance and the posture change is made by, for example, adding a mirror on an optical path between a light source and an imaging element and driving the mirror in a direction in which vibration due to the shaking disturbance, the posture change, and the like is counteracted when reflected light from the subject is collected to make the reflected light incident on the imaging element.
As a technology to drive a mirror in accordance with a shaking disturbance or a posture change, for example, a biaxial piezo imaging device and a biaxial cymbal imaging device are known. In the biaxial piezo imaging device, generally, the influence of vibration due to the shaking disturbance, the posture change, and the like was reduced by driving a mirror in two axes directions using a piezoelectric element. In the biaxial cymbal imaging device, generally, the influence of vibration due to the shaking disturbance, the posture change, and the like was reduced by driving a mirror attached to a rotating body that rotates biaxially using a motor.
It is to be noted that technologies related to the present invention are described in PTL 1, PTL 2, and NPL 1, for example.